Phantom and in vivo validation of a novel contactless registration method for robot-assisted SEEG surgery

In recent years, robot-assisted stereotactic system has been widely used in stereo-electroencephalogram (SEEG) surgery. However, current registration mainly based on bone-fiducial registration (CBR) is limited by the inconvenient of repeated contact during the process. Here, a novel contactless optical-tracking registration (OTR) were applied for SEEG using robot-assisted stereotactic system. To demonstrate the accuracy and convenience of the novel OTR method compared with contact CBR method during the robot-assisted SEEG in phantom and animal model study.

A head phantom and 12 Bama pigs (Sus scrofa domestica) with six under CBR and six under OTR were selected for the SEEG. Procedures were performed using the robot-assisted stereotactic system in different registration methods. The positioning error and time consumption during the registration process were assessed to compare the accuracy and convenience of OTR and CBR. Besides, two new users for the robot-assisted stereotactic system were selected for the learning curve analysis.

The mean positioning errors in OTR group of the target and entry points were 1.68 ± 0.80 mm and 0.76 ± 0.39 mm. And in CBR group, mean positioning errors of the target and entry points were 1.49 ± 0.79 mm and 0.70 ± 0.33 mm. The registration time of OTR method (99.71 ± 1.08 s) was significantly shorter than that using CBR method (241.29 ± 28.95 s) (p value < 0.001). During the learning curve analysis, it is earlier for the users to go under OTR than CBR to reach a preferable entry error of 0.5 mm.

The contactless OTR method can effectively reduce the time consumption during the registration process while maintaining the accuracy with CBR method. The novel method not only simplify the procedure by optical-tracking but also shorten the new user's learning curve compared with current method.